According to a computer simulation based on real-world data, hospitalized patients given acid-reducing drugs in the hospital have a higher risk of dying compared to those who do not receive the drugs. The study is published in the Journal of General Internal Medicine by a team from the University of Michigan Medical School and VA Ann Arbor Healthcare System.

Using a computer model the team was able to calculate that 90% of inpatients who were first prescribed proton pump inhibitors (PPI) in the hospital and 80% of patients who were already on PPIs when they arrived at the hospital had a higher risk of dying if they were treated with these drugs while hospitalized versus those who never received the medications. The researchers attribute this increased risk to the fact that reducing acid in the stomach can increase the risk of infections that pose a serious risk to hospitalized patients (ie, pneumonia, Clostridium difficile). In the case of pneumonia, suppressing acid production may increase the amount of bacteria in the stomach and throat, which can then get into the lungs and cause pneumonia. More research is still needed on why PPI use increases a patient's vulnerability to hospital-acquired infections.

“Many patients who come into the hospital are on these medications, and we sometimes start them in the hospital to try to prevent gastrointestinal, or GI, bleeds,” says lead author Matthew Pappas, M.D., MPH. “But other researchers have shown that these drugs seem to increase the risk of pneumonia and C. diff, two serious and potentially life-threatening infections that hospitalized patients are also at risk for,” he continues. “Our new model allows us to compare that increased risk with the risk of upper GI bleeding. In general, it shows us that we're exposing many inpatients to higher risk of death than they would otherwise have – and though it's not a big effect, it is a consistent effect.”

Based on these new findings, the researchers believe very few hospital patients should start taking or continue on PPIs as a preventive measure against gastrointestinal bleeding. Nationally, some efforts have already shown ways to reduce the rate of new PPI prescriptions to hospitalized patients.

The authors also point out the importance of using computer models to answer important medical questions. In order to come to a similar conclusion about PPI use and mortality risk, a clinical trial of more than 64,000 patients would be needed, and the likelihood of this type of study being funded would be slim.

"Physicians have an instinct to want to prevent very bad, though rare events – but everything we do carries risks. We need to be mindful of the things we are doing to prevent rare outcomes, and keep the risks in perspective. Computers can help.” said Pappas.